A failure of a semiconductor device may occur due to electro-migration. The term “electro-migration” refers to a phenomenon wherein when a current is supplied to flow through (wiring) lines for a power supply, etc., metal atoms are migrated with momentum exchange between electrons flowing through the lines and metal ions included in the lines. The migration of metal atoms causes wiring to electrically disconnect or break. Thus, the electro-migration raises a problem in trying to ensure reliability of the semiconductor device.
To overcome the above-described problem, the semiconductor device includes a failure prediction circuit. The failure prediction circuit includes a conductive pattern coupled between a power supply line at a high potential and a power supply line at a low potential, and monitors a voltage at the conductive pattern.
Because the electro-migration occurs when a current is supplied to flow through a (wiring) line, the electro-migration may occur not only in a power supply line, but also in a signal line. In other words, the electro-migration may occur in a line for electrically interconnecting logical circuits and transmitting a signal, and may cause an electrical disconnection of the line between the logical circuits. Such a failure is locally generated inside a function block formed in the semiconductor device, and is not detected in a circuit for predicting a typical failure. It is, therefore, difficult to improve reliability.